On the title screen, pressing Up/Select/Left/Right/A/A/B will cause a level select option called "Dream Select" to appear below the Start option. After scrolling down to the Dream Select option, pressing the A button will play a short tone that indicates one additional level has been selected. For example, if you press the A button 3 times, you will hear 3 chimes, and then pressing the Start button will take you to the 4th level in the game.

Near the halfway point of Dream 2: The Flower Garden, if you use the Bee to fly over a large body of water, you will land on a platform that is blocked off by a small tunnel that can only be accessed while riding the Lizard. Flying back over to the other side will spawn a unique enemy that does not appear anywhere else in the game: a blue rabbit that throws green Easter eggs and will charge at you if you walk too close to it.

In the North American and European releases of the game, the cigars being smoked by Flip and the Gorilla are removed. Despite this, the game's manual in these regions features artwork of the Gorilla smoking a cigar, and the Gorilla's sprite still has curled lips as if it were holding a cigar in its mouth.

The Japanese title screen is based on the logo used for the original Japanese release of the 1989 film "Little Nemo: Adventures in Slumberland", which the game is based on. The international logo is completely original and puts more emphasis on the game's subtitle. Although Nemo himself was removed from the title screen, the graphic can still be found in the data of the North American and European versions. Additionally, some larger stars were added to the background and the corner decorations at the bottom of the screen were removed to fit extra copyright information.

The attack pattern of the Manta Ray boss in Dream 8: Nightmare Land differs slightly in the North American and European releases of the game.